Techniques such as Raman and fluorescence spectroscopy use a beam of light to identify molecular constituents of a sample. Raman, for example, relies on inelastic scattering of monochromatic light, usually from a laser in the visible, near infrared, or near ultraviolet range of the spectrum.
Many Raman and fluorescence systems now use remote probes, wherein the laser excitation and collected spectra are carried over optical fibers to and from a probe head. The lasers used in these and other spectroscopic techniques are high-powered units, the light of which can be dangerous to the unprotected eye.
Current practice to protect the user from unwanted reflected laser light, and to keep a Raman probe from collecting unwanted external light, is to encase the reactor in foil and/or switch off all the lights close to the reactor. FIGS. 1A, B illustrate schematic installations for Raman and other optical probe sensors. Those of skill in the art would appreciate that a more robust solution is warranted.